Prolonged gonadotropin stimulation for assisted reproductive technology cycles is associated with decreased pregnancy rates for all women except for women with polycystic ovary syndrome.

ABSTRACT

PURPOSE: To determine if etiology of infertility modifies the relationship between the duration of ovarian stimulation and success during assisted reproductive technology (ART) cycles. METHODS: A prospectively collected database was analyzed in an academic infertility practice. Eight hundred and twelve infertile women undergoing their initial fresh embryo, non-donor in vitro fertilization (IVF) or Intracytoplasmic Sperm Injection ICSI) cycle between January 1999 and December 2010 were evaluated. Clinical pregnancy was the main outcome measured. RESULTS: Out of 663 cycles resulting in oocyte retrieval, 299 produced a clinical pregnancy (45.1%). Women who achieved a clinical pregnancy had a significantly shorter stimulation length (11.9 vs. 12.1 days, p = 0.047). Polycystic ovary syndrome (PCOS) was the only etiology of infertility that was significantly associated with a higher chance for clinical pregnancy and was a significant confounder for the association of duration and success of treatment. Women with 13 days or longer of stimulation had a 34 % lower chance of clinical pregnancy as compared to those who had a shorter cycle (OR 0.66, 95% CI0.46-0.95) after adjustment for age, ovarian reserve, number of oocytes retrieved, embryos transferred and PCOS diagnosis. CONCLUSION: Prolonged duration of stimulation is associated with decreased ART success for all couples, except for women with PCOS.